Process of refining wood rosin



Patented Dec. 3, 1929 I rnvrn w. numrnnnv, o r novnn,

NEW JERSEY, we nnnvrrr'n. ,Bnnr, or non!- OAK, DELAWARE, ASSIGNORS THERCULES POWDER COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OFDELAWARE "PROCESS OF REFINING WQQD RGSIN Ito Drawing, Application tiledMay 1 15, The object of our invention isto sotreat wood rosin as toproduces rosin so highly refined that it is adapted for use inmanuiactu'ring high grade rosin soaps.

A blown. process of producing wood rosin of alower grade consists ingrinding wood and stumps from pine trees, placing the wood stock inlargedigesters, passing steam through the stock and thus driving oil aconsiderable to quantity of turpentine, flooding the stock with gasolineor other solvent, thereby extracting certain materials, chiefly rosin,pine oil and various color lood1es,pass1ng the gasoline solution,commonly hown as drop liquor 6 through suitable evaporators, andtractionally removing the gasoline and pine oil. The pine oil producedby the distillation is relined and sold. The recovered gasoline is againused in the process.

The recovered rosin is a marketable prod not but is satisfactory onlyfor such uses as sizing inferior grades of paper and use in.

- inferior iades of varnish. It is possible, however, y a subsequentrefining (distilling) operation, not involving theemployment ofour'invention, to so far refine this rosin as to adapt it for use in.sizing hi h grades of paper and making the best varnish, but suchrefined rosin, although of high grade, will not reduce soaps or, limedvarnishes of satisactory color. This discoloration ofthe soaps.isundoubtedly due to some volatile color bodies that are carried overin the distillation of the rosin. These color bodies are notvisrosincomes into contact with the alkali used in making soap, or withthe lime used in the manuiacture.oicertain varnishes, or in the mereheating of resin, while in contact with 7 air, in the manufacture ofvarnish generally, a marked coloration develops. To overcome thisdificulty we subject the drop liquor, referred to in the abovedescription of a known to twenty per cent solution of rosin in sol. ventconsisting mostly of gasoline. Pine 01ltdroxid or sodium, hydroxid (NHMHor ibly'present in the rosin itself, but when they process forextracting resin from wood, to a 1923'. Serial to. 639,205.

and some turpentine are also present in the solvent. I 1

The drop liquor is washed with an aqueous solution of alkali, preferablyammonium hyli'aOH). The exact strength of the solution 1s apparently notimportant. As an example, a two-tenths of one per cent strength alkalisolution of NH OH or NaOl-ll in weight equal to the weight of the dropliquor is generally found eficacious. Toobtain a greater purityingaction, a'larger quantity of alkali can be used. llt is sometimesadvisable to use an alkali concentration as high as I 0.8%. An evenhigher limit, perhaps 2%, might sometimes be of advantage. Thisvtreatment will remove from five to fifteen per centof the rosin fromthe drop liquor by reason of its neutralization b the alkali. It may beadvantageous to a d a small amount of sodium chloride, or otherelectrolyte, in order to hasten the breaking of the emulsion. A. certainquantity of the ammonium or sodium salts of rosin acids are formed. Aportion of the \color bodies which exert-a harmful sheet in themanufacture ofl'soaps is carried down in the alkali washing medium.These color bodies in the alkali solution belong, it is believed, to theindefinite class of substances known as hic acids.

. After thorough agitation, the mixture is allowed to stand and theaqueous washing me: dium separates and is easily removed. The treateddrop liquor'is then washed with water and is then given the regulardistillation treatment for drop'liquor, whereby the gasoline and pineoil are separated from the rosin.

Although this resin is of substantially higher quality than would beproduced it the alkali refining'process were omitted, it is desirable,if notjnecessary, to further refine the rosin. l/Vhileithe additionalrefining process is not our invention per se; its use in connectionwithour alkali refining process is'new with us, and inasmuch as itsemployment may be necessary in order to secure the ultimate productdesired, it will be briefly described; reference being madejto anotherapplication filed'by'Kaiser and Langineier May 15, 1923;, 3

I Serial No. 639,054, for a more specific disclosure.

The rosin is (preferably) first heated under a high vacuum to atemperature of about 480 F. and preliminarily distilled. It. is thenheated to a higher temperature. With a vacuum of 28 inches, thepermissible temperature range wouldbe from 500-7 F., preffractionalcondensation. It may! be still, is a convenient and effective heatingmedium. It is advisable to inject superheated steam into the rosin toaid in carrying out the distillation. The rosin is then subjected topassed I through three condensers maintained at temperaturesrespectively of 400 F.,350 F. and

300" F. Any uncondensed rosin mist or vapor may be conveyed to anendless circuit of gasoline, kerosene orother solvent and therebydissolved. The solvent may be carried in water-cooled pipes and thewater of condensation settled out in a separating tank.

The rosin condensed in the two con ensers subjected to the highesttemperatures is substantially free of those color bodies which, if itwere not for our alkali refining process, would be present and which, ifpresent, would 'unfit the rosin for use in the manufacture of rosinsoaps or limed rosin varnishes of satisfactory color.

Ammonium hydroxid is preferred as a treating agent for the drop liquorin the alkali refining step of our process. But any other alkali, asNaOI-I, or Na GO may be used. The rosin dissolved in the alkali solutionmay be recovered by acidification. When ammonia is employed, by heatingthe ammoniacal solution of rosin and coloring matter, there is adifferential separation of rosin and coloring matter as the ammonia isdriven ofi. The rosin of highest quality in the wash liquor isprecipitated first and can be separated and is a salable product. Therosin that is precipitated toward the last is very dark and contains alarge percentage of coloring matter. While the uses of the last fractionthat precipitates are very limited, it is but a small fraction of thetotal amount of rosin in the drop liquor, and if it were discarded asworthless, its loss would be far more than compensated far by thesubstantial increase in quality and value of the large proportion ofrosin that is ultimately recovered as a high grade rosin adapted for themanufacture of rosin soap as well as for other uses,

'boiling petroleum such as sizing high grade paper and in themanufacture of varnish.

While in the claims we havereferred to the process as one adapted to themanufacture of rosin soaps, it is intended to cover all uses for whichthe rosin may be adapted, as, for example, the making-of limedvarnishes, as he'reinbefore specified, or the sizing of high gradepapers.

Having now fully described our invention, what we claim and desire toprotect by Letters Patent is 1. The process ofproducing rosin adapted tothe manufacture of products of good color as herein specified, whichcomprises treating with a dilute alkali solution liquor obtained in theextraction of rosin from wood by means of a low boiling petroleumdistillate, separating from the drop liquor the alkali together with thecolor bodies carried down thereby, liquor to separate out most of thelow boiling petroleum distillate from the rosin, distilling the rosinunder a vacuum, and then condensing the rosin at a temperature withinabout the range 300 F.400 F.

2. In the manufacture of rosin adapted to the manufactureof products ofgood color as herein specified, he process which comprises treating thedrop liquor obtained in the extraction of rosin from wood by means of alow boiling petroleum distillate with an alkali in quantity insuflicientto efiect saponification of over about 15% rating from the drop liquorgether with the color bodies carried down thereby, distilling the dropliquor to separate out most of the low boiling petroleum distillate fromthe rosin, distilling the rosin under a vacuum and condensing a fractionof the vaporized rosin at a temperature within about the range 300 F.400F.

, 3. The process of producing rosin adapted to the manufacture ofproducts of good color as herein specified, which comprises treating thedrop liquor obtained in the extraction of rosin from wood by means of alow distillate with an alkali in amount not substantially in excess ofabout 2%, separating from the drop liquor the alkali together with thecolor bodies carried down thereby, distilling the drop liquor toseparate out most of the low boiling petroleum distillate from therosin, distilling the rosin under a vacuum, and condensing a fraction ofthe vaporized rosin at a temperature of the rosin, sepawithin about therange 300 F.4:00F.

the alkali tothe drop a distilling the drop l. In the manufacture ofrosin adapted to the manufacture of products of good color as hereinspecified, the process which comprises treatmg with a solution ofammonium hydroxid the drop liquor obtained in the extraction of rosinfrom wood by means of a low boiling petroleum distillate, separatingfrom the drop liquor the ammoniacal memes solution together with thecolor bodies and some rosin that are carried down thereby, distillingthe drop liquor to separate most of the low boiling petroleum distillatefrom the resin, heating the am'moniacal solution rosinland coloringmatter, thereby differentially separating the resin and coloring matteras the ammonia is driven oil, and

, separating out precipitated resin.

prises treating drop liquor obtained 5 In the manufacture of rosinadapted to the manufacture of vproducts of good color as hereinspecified, the process which comin the extraction of rosin from wood bymeans of a low hoiling petroleum distillate with an alkali in snfiicientquantity to saponify from about 5%l5% of the resin, agitating themixture, allowing the mixture to settle, Withdrawing the alkali togetherwith the color bodies carried down thereby, washing the drop liquor withWater, and fractionally distilling as the low boiling petroleumdistillate.

In testimony of which invention, I, IRVIN HUMPHREY, have hereunto set myhand at Kenvil, N. J., on this llth day of April, 1923, and I, L vu'r N.BENT, have hereunto set my hand at Wilmington, Del, on this 25th day ofApril, 1923.,

IRVIN W. HUMPHREY. LEAVITT N. BENT.

